Nbs Owners...afm Problems. Must-read

[98 Z71 SLT]

Just found out about a new TSB from GM. Deals specifically with NBS and 5.3 / 6.0 engines.

 

People are complaining about cold-start tick that lasts for around a minute.

 

Turns out, the AFM lifters are failing. Already.

 

GM has authorized replacement of ALL lifters, if the customer complains of a rattle / tick on cold starts.

 

PIP 4344

document id 2065710

 

What the heck?? At least the engine is quiet in my NBS '08...does this mean it will get loud??

 

Doesn't GM test this stuff before it goes into mass-production ??? I'm sure alot of us are really starting to lose some faith here...

[nakedicarus]

 

Perhaps Mike (M. Cueva) could post this bulletin on here?

[d3athsong]

This doesnt mean you will have a problem, it means some people have had this problem. Did you ever get that vibration fixed?

[redvett]

GM and other MFR's test ,test,test but the problem is the supplier. They make a contract to make a product and then when GP3 production parts come out its been cheapened. Result is failures. I have seen it for many many years. This does not just apply the Cars & trucks but everything.

[jrrod2004]

you got it....give me a min

[jrrod2004]

Service Information

Document ID: 2065710 #PIP4344: Short Duration Cold Start Lifter Tick Noise - keywords 5.3 6.0 cam engine L76 LC9 LFA LH6 LMG LS4 LY5 oil pressure start - (Feb 18, 2008)

 

 

Subject:Short Duration Cold Start Lifter Tick Noise

 

 

 

 

Models:2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe

 

 

2007-2008 GMC, Sierra, Yukon

 

 

2007-2008 Chevrolet Impala

 

 

2007 Chevrolet Monte Carlo

 

 

Equipped with the 5.3 or 6.0 Active Fuel Management engines

 

 

 

 

The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

 

<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2065710&from=ns#ss1-2065710">

Condition/Concern:

A customer may comment on a cold start engine tick noise. The noise explained may be an extended duration noise related to AFM (Active Fuel Management) valve lifters. The noise may repeat on subsequent cold starts. Noise will be camshaft speed and may last over 1 minute. Noise will only occur after a cold soak that is greater than four hours in duration.

 

<A href="http://gsi.xw.gm.com/si/showDoc.do?docSyskey=2065710&from=ns#ss2-2065710">

Recommendation/Instructions:

Complete the current SI diagnostic for any symptom or DTCs found. If an extended duration lifter tick noise has been verified (usually greater than 1 minute), and the noise is considered excessive and repeatable, lifter replacement may be required. To repair this concern all lifters should be replaced with lifters obtained through GMSPO. There is no special part number necessary.

 

Note: The 6.0L engine, RPO code LFA has been built with updated lifters since 1-28-2008. 6.0 LFA engines built prior to 1-28-2008 may need the lifters replaced if the customer concern is as described in this PI.

 

Note: If a cold start lifter tick noise has been verified on any other 5.3L or 6.0L AFM engine, lifter replacement may be necessary. These engines (L76 LC9 LH6 LMG LS4 LY5) do not have a build date released for updated lifters.

 

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

 

 

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

that truly sucks

[2007silveradonbs]

So how many people are going to go out and start their trucks and listen more closely to their engines than they normally do?

[excaliber]

This is not good. The AFM is one of the few things I do not like about the GM trucks. I wish they would just eliminate it all together.

I was told several months ago that the AFM was going to be an issue with these trucks. I guess they were right.

[HawkeyeOC]

Darn! Heard the cold start ticking a couple of times on my 5.3. Hello dealer!

[jrrod2004]

print it out and then take it and shove it up their asses

[VMax2007]

Goddammitanyway

[jrrod2004]

Sorry, I couldnt help it....

[slomo007]

So if you are willing to put up with the ticking at start up, is there really any risk to just not caring about it?

 

I have never heard the ticking by the way, but then again I've never listened for it.

[jdolotina]

What a bunch of crap sometimes I wish I waited for an 08 instead of jumping the gun and buying the first year model. Sometimes, it sucks being a ginnie pig...

 

Josh